What is the meaning of "Sikim be'Eineichem"?
Rashi and Rashbam: It means 'sharp pegs in your eyes'.
Rashbam: 'Sharp thorns that stab you in the eyes'. 4
Targum Onkelos: It means 'armed brigades'.
Targum Yonasan: 'They will look at you with an Ayin ha'Ra'.
Ramban: Causing you to emulate their abominations and to worship idols like them, as the Torah specifically writes in Shemos 23:33.
And what is the meaning of "Tzeninim be'Tzideichem"?
Rashi #1: It means 'a wall of thorns'. 1
Rashi #2 (in Mishlei) and Targum Onkelos: 'Surrounded by armies' 2 or 'brigands and robbers'.
Ramban and Rashbam #1 (citing Menachem ben S'ruk): 'Sharp thorns 3 in your sides'.
Rashbam #2: It means 'to cool you down'. 4
Targum Yonasan: 'They will surround you with shields'. 5